Question

约分分式 （1）x-y/-x+y （2）(x+y)^2/2(x+y)^3 （3）2mn/2m^2+4mn (4)2(a-

Answer 1

(x-y)/(-x+y)=(x-y)/-(x-y)=-1

(x+y)^2/2(x+y)^3=1/(2(x+y))

2mn/2m^2+4mn=(n+4nm^2)/m,2mn/(2m^2+4mn)=n/(m+2n)

2(a-b)^2/(a^2-b^2)=2(a-b)^2/((a-b)(a+b))=2(a-b)/(a+b)

(x^2+6xy+9y^2)/(x^2-9y^2)=(x+3y)^2/((x-3y)(x+3y))=(x+3y)/(x-3y)